Basic concept of flanges

Definition and name
Definition: Flange is a ring structure used for the connection of equipment, pipes and other components, through bolts, nuts and other fasteners to achieve a close connection between the components.
Name origin: the word "flange" comes from the transliteration of English "flange", which is also called flange flange disc or flange in Chinese.
Role and function
The main function of the flange is to connect pipes, valves, pumps and other equipment or components to ensure the smooth flow of fluid or gas in the pipeline system.
It guarantees the safety and stability of the mechanical system by providing a strong and sealed connection point.
Structure and type
Basic structure: The flange is usually composed of two flanges and corresponding bolts, nuts and gaskets. The flange is provided with a bolt hole for fastening with another flange through a bolt.
Type classification: According to the use, structure and connection method, flanges can be divided into a variety of types, such as flat welding flanges, butt welding flanges, socket welding flanges, loose sleeve flanges, threaded flanges. Each type has its own specific application scenarios and advantages and disadvantages.
Material and manufacturing
Material: Flange material variety, including carbon steel, low alloy steel, stainless steel, etc., to meet the needs of Different working conditions.
Manufacturing process: The manufacturing process of the flange includes heat treatment, machining, surface treatment and inspection and packaging steps. Among them, heat treatment is used to eliminate internal stress, improve organizational properties and increase mechanical strength; Machining ensures the dimensional accuracy and surface quality of the flange; The surface treatment improves the corrosion resistance and aesthetics of the flange; Inspection and packaging are the key steps to ensure the quality of the flange.

Connecting Flange head installation and maintenance

Installation steps
Preparatory work
Check the appearance of the flange head to ensure that there is no damage, rust or deformation.
Clean the surface of the flange head, especially the sealing surface, to remove oil, dust and other impurities.
Prepare suitable bolts, nuts and gaskets to ensure that the material and specifications meet the design requirements.
Mounting gasket
Place the gasket on the sealing surface of one flange head to ensure that the gasket is flat and free of wrinkles.
The choice of gasket should be based on the medium, temperature and pressure and other conditions, commonly used materials are rubber sheet, rubber asbestos board and so on.
Butt flange
Butt the two flange heads together, making sure the gasket is between the two flanges.
Check whether the flange holes are aligned and the deviation should be within the allowable range.
Fastening bolt
Put on the bolts and tighten them using a wrench or torque wrench.
When tightening bolts, follow the principle of symmetry and uniformity to avoid deflection of the flange head or loose sealing.
The tightening torque of the bolt should meet the design requirements, too tight or too loose may affect the sealing effect.
Check tightness
After installation, the flange connection should be checked for tightness.
Air pressure test or water pressure test can be used for detection to ensure that there is no leakage.
Maintenance precautions
Periodic inspection
Check the flange connection regularly, including the tightening of bolts, the wear of gaskets, etc.
If the bolt is loose or the gasket is aging or damaged, handle the problem in time.
Cleaning and maintenance
Clean the oil, dust and other impurities on the surface of the flange head regularly to keep it clean and dry.
For the flange connection that is not used for a long time, anti-rust treatment should be done to prevent rust.
Replace gasket
The gasket is one of the wearing parts in the flange connection and should be replaced regularly according to the use and medium conditions.
When replacing a gasket, select a new gasket of the same material and specifications as the original gasket.

Material and manufacture of flanges

Material: Flange material variety, including carbon steel, low alloy steel, stainless steel, etc., to meet the needs of different working conditions.
Manufacturing process: The manufacturing process of the flange includes heat treatment, machining, surface treatment and inspection and packaging steps. Among them, heat treatment is used to eliminate internal stress, improve organizational properties and increase mechanical strength; Machining ensures the dimensional accuracy and surface quality of the flange; The surface treatment improves the corrosion resistance and aesthetics of the flange; Inspection and packaging are the key steps to ensure the quality of the flange.

Flanges are widely used in petroleum, chemical, food, medicine, textile, machinery and other industrial fields, and are indispensable components in pipeline connection.